The parenteral administration of beneficial agents to a needy recipient is a well-accepted and established clinical practice. Presently, a beneficial agent often is administered by using a parenteral delivery system. The parenteral delivery system comprises a formulation chamber containing an active agent, that is mixed with an incoming parenterally administrable fluid to form an administrable fluid agent formulation. The fluid is supplied from a fluid container suspended above the formulation chamber. While the form of parenteral administration is widely used and can lead to acceptable therapy, there is still a great deal of dissatisfaction with this kind of delivery system that lends itself to improvement. Mainly, the value of the system can be improved and its therapeutic usefulness increased if (1) a means and method are made available for governing the rate of introduction of active agent into an intravenous fluid; and, (2) a means and method are made available for governing the rate of introduction of active agent into an intravenous fluid coupled with means for controlling the flow rate of the fluid agent formulation to a recipient.